Sign for an automobile window



FIG. 1 is a front elevational view of a sign for an automobile window showing my new design;

FIG. 2 is a top plan view thereof, the unshown bottom view being of identical appearance;

FIG. 3 is a rear elevational view thereof; and

FIG. 4 is an end elevational view thereof, the unshown opposite end being of identical appearance. 

The ornamental design for a sign for an automobile window, as shown and described. 